The present invention relates to polymeric compositions having high impact strength, comprising a major portion by weight of a fluorovinylidene polymer or a copolymer of fluorovinylidene and a substantial quantity of tetrafluoroethylene, and a minor portion by weight of a methyl methacrylate polymer; and a process to produce the same.
The use of methyl methacrylate polymers in impact resistant compositions is known, particularly from European Patents Nos. EP-A-093,038 and EP-A-101,048. French Patent No. FR-A-2,104,545 teaches the polymerization of up to 150 parts by weight of methyl methacrylate with 100 parts by weight of suspension polymerized polyvinylidene fluoride (as used herein, "PVF"), to obtain films having excellent electrical properties.
The use of polymeric sheets based upon polymethyl methacrylate (PMMA) is also well known in the art. Such sheets are used in extremely varied applications, especially in fields in which glass was previously used, because of their transparency, lightness, and low cost of manufacture. These sheets, however, are disadvantageous because of their lower impact strength as compared to safety glass and polymeric materials such as polycarbonate. They also exhibit inferior flame and bullet resistance as compared to polycarbonate.